Traveltime and reaeration of selected streams in the North Platte and Yampa River basins, Colorado

Traveltime characteristics were measured using rhodamine WT dye as a tracer in the Canadian and Michigan Rivers in the North Platte river basin and in the Yampa, Elk, and Williams Fork Rivers, and Trout and Fish Creeks in the Yampa River basin of Colorado. Reaeration coefficients were determined by use of the modified-tracer techniques using ethylene and propane gas for selected stream reaches during low-flow conditions. Stream reach velocities determined during traveltime and reaeration measurements ranged from 0.09 mi/hour at 5.1 cu ft/sec on the Canadian River to 4.04 mi/hour at 746 cu ft/sec on the Williams Fork. A modified longitudinal dispersion model or results from cumulative traveltime curves were used to estimate traveltimes in the measured streams for streamflow conditions other than those measured. Traveltime-discharge curves were developed by using the estimated and measured traveltimes. Reaeration coefficients were determined for 20 different subreaches in the study area. Rearation coefficients were determined for 20 different subreaches in the study area. Reaeration coefficients ranged from 1.6/day in a pooled subreach of the Yampa River Craig, Colorado, to 98/day in a turbulent subreach of Trout Creek near Oak Creek, Colorado. (USGS)